1. Field of the Present Invention
The present invention is in the field of data processing systems and, more particularly, conserving the amount of energy consumed by a data processing system.
2. History of Related Art
Many computer-based services and applications are characterized by a time varying workload. In typical multiprocessor server systems, however, the energy consumed by the system's main processors varies substantially less significantly than the workload. More specifically, the main processors consume significant energy even when they are idling or otherwise doing little actual work. In such systems, energy efficiency is undesirably low during times of low system utilization.
Various efforts to improve energy efficiency have been proposed. For example, clock gating, which is used in substantially all processors, may somewhat reduce the amount of power consumed during low utilization periods. Nevertheless, processors are generally characterized by relatively large leakage currents that result in significant energy consumption even during periods of zero utilization. While other energy conservation techniques, such as frequency and voltage scaling, can reduce energy consumption, they are generally difficult to implement in multiprocessor systems and may provide unacceptable performance when rapid responses are needed. It would be desirable, therefore, to implement a system and method for conserving energy in a multiprocessor data processing system.